The Seattle Chamber Music Festival launched into the final week of concerts of its summer season on Sunday with some Romantic masters, and a nudge into the 20th century.

The concert began with the Rondo for Violin and Piano in B minor by Franz Schubert, who didn't write much chamber music at all, unless you count the lieder. Anna Polonsky launched the dramatic venture with regal chords on the piano, and violinist Amy Schwartz Moretti answered with her swashbuckling violin. The primary strength of the Rondo is workout it gives the violinist. There was plenty of juice, especially in the second of the two movements. Romantic composers are prone to mood swings, and it gave Moretti and Polonsky plenty to play with, brilliantly.

The richest musical moments came in the Brahms Sonata No. 1 for Cello and Piano in E minor, Op. 38, performed by the tandem of cellist Robert deMaine and pianist Adam Neiman. It was a rich, warm bath of melody and fugal countermelody, an instrumental dialogue that got more dramatic and grand as it reached the peak in the middle of the first movement. Brahms, like Beethoven before him, was brilliant at creating lighter center movements, to contrast all the heaviness in the bookends. The Allegretto was that light balance, performed by these two gentlemen with the apt drama of a ponderous cup of tea.

This set up the finale's high drama from the piano, answered by the cello, as the dialogue became an elegant trade of flourishes.

The post-intermission half was occupied by William Walton's Quartet for Piano and Strings, a work never before heard at this festival. Walton was one of the grand old men of English music in the 20th century, but how do the compositions of his youth hold up?

Quite solidly, as it turns out. There was plenty of mature, meaty music here. And if you think Romantic composers have mood swings, try teenagers. The first two movements are filled with vigor and synchronized pyrotechnics among the three string parts. The audience chuckled as the musicians paused before the gentle Andante Tranquillo to pull the many broken horsehairs from their bows.

One of the great joys of this summer series is seeing and hearing new blends of individual musicians. There are characters like violist Marcus Thompson, who has been around this festival approximately forever, next to relative newcomers like the brilliant cellist Julie Albers, a bow's length from the young but accomplished artistic director/violinist James Ehnes, all backed by Andrew Armstrong on piano.

The expectation level is high at this festival, producing constant gems as they have. But the musicians all seem very comfortable with excellence, which makes the experience a joy.